In a ring-spinning frame, the yarn is supplied in the form of packages of roving which is drafted and spun into yarn as it is wound onto bobbins which are mounted on spindles for rotation about a vertical axis. The roving from the packages passes through drafting rolls and yarn guides to a traveler ring which orbits the bobbin and traverses the length of the bobbin to build a compact package of spun yarn on the bobbin. The traveler is carried by the ring rail which normally builds the package starting at the bottom and traverses upwardly.
The spindles have an area immediately below the bobbins, referred to as the whirl, onto which several wraps of yarn are wound as the ring rail traverses down below the bobbin prior to stopping the frame for doffing of the full yarn bobbins. This assures that as the full bobbins are doffed, the yarn remains threaded up from the drafting rolls through the yarn guide and traveler to the spindle. Removing the full bobbins separates the yarn between the bobbin and the spindle whirl, leaving several wraps of yarn on the whirls. After empty bobbins are placed onto the spindles and the frame is restarted, a few more wraps are added to the whirl before the ring rail is raised to its normal operating position where the yarn is wound onto the empty bobbins.
Unless the wraps of yarn are removed from the whirl, with each doff a few more wraps of yarn are added to each spindle whirl, and pieces of yarn and fibers will eventually be thrown from the spindle whirls and may get into the rings, travelers and yarn being processed. This can result in yarn defects and may even cause the yarn to break. Through the years there have been many different attempts to provide devices to efficiently remove the wraps of yarn from spindle whirls. Machine operators have used brushes, various abrasive materials and rotating discs to press against the rotating spindle whirls, thus tearing the yarn from the whirl. This tended to be slow and if not done at frequent intervals, resulted in large quantities of fiber and yarn pieces being thrown about. Variations of these approaches included adding a vacuum source to collect the fiber and yarn pieces removed from the whirl, but it still required required a person to operate it.
More recently, blade-like devices have been mounted adjacent the base of each spindle. Each blade has a flat target area arranged so that a stream of air directed against the blade assembly at right angles to the side of the frame causes the end edges of the blade to move against the spindle whirl, impinging the yarn wraps and causing them to break up and be thrown off. Manufacturers of traveling blowing and suction machines for ring spinning frames have provided special blowing outlets to actuate these whirl-cleaning devices. Such blowing outlets use the same relatively low pressure exhaust air that is used for cleaning the frames. In some installations, the blowing outlets blow continuously, thus activating the whirl-cleaning blades every time the traveling cleaner device passes, as frequently as every 4 to 15 minutes. Not only does this continuously divert exhaust air from cleaning other parts of the spinning frame, but such frequency is unnecessary and accelerates the wear on the whirlcleaning blades. In other installations, the blowing outlets are equipped with dampering devices and complex control systems so that the whirl-cleaning blades are actuated only when needed, once after each doff.
At least one spinning frame manufacturer provides relay contacts which are controlled by the builder motion for the ring rail of the spinning frame. The contacts are actuated several minutes after the start of a spinning cycle when the ring rail is operating near the top of the bobbins, farthest from the spindle whirls to initate mechanical or optical signals which, in turn, actuate dampering mechanism in the exhaust air supply to the whirl-cleaning outlets of the traveling cleaner. In such a case, the entire flow of exhaust is diverted to operate the cleaning blades and is lost for cleaning other parts of the spinning frame during actuation of the dampering mechanism.